The Allouville oak sits enthroned on the small square that bears the name of its savior, Robert Bourdu. The 1,200-year-old tree was withering away in the 1980s, a victim of tourist traffic that was suffocating its roots. A professor of plant physiology from Versailles, he fought for the survival of this remarkable tree he would come to visit until the end of his days. While only 30% or 40% of the oak is alive, it still has majestic leaves and produces acorns. It can die tomorrow or live another hundred years.